February 25, 2014

MEMORANDUM

SUBJECT: Development of Air Quality Reference Case Upstream and Portable Fuel

Container Inventories for Tier 3 Final Rule

FROM: Rich Cook, Environmental Scientist

Margaret Zawacki, Environmental Engineer Zoltan Jung, Mechanical Engineer Assessment and Standards Division, Office of Transportation and Air Quality

TO: Docket

The purpose of this memorandum is to document the methods used to develop reference case
upstream and portable fuel container inven tories used in air quality modeling for the final Tier 3
rule. While the Tier 3 final rule has no impact on portable fuel container (PFC) or upstream emissions, a significant number of mod ifications were made to the 2007 v .5 platform inventory to

create re ference case PFC, point and nonpoint source inventories which account for expected impacts of renewable fuel requirements under EISA

, as estimated by Annual Energy Outlook (AEO) 2013, 1 as well as impacts of recent 2017

- 2025 light duty vehicle greenhouse gas emission standards and heavy

- duty greenhouse gas standards

.
Upstream Impacts

In addition to the effects of increased renewable fuel use on emissions from the vehicles and equipment that use the fuels, there are shifts in the fuel production and trans port/distribution methods that can have substantial impacts on emissions. These "upstream" emissions are associated with all stages of biofuel production and distribution, including biomass production (agriculture, forestry), fertilizer and pesticide prod uction and transport, biomass transport, biomass refining (corn or cellulosic ethanol production facilities), biofuel transport to blending/distribution terminals, and distribution of finished fuels to retail outlets. Additionally, changes in agricultural economics associated with increased biomass production can result in shifts in related agricultural production, such as livestock. Furthermore, greenhouse gas2

emission standards impact production, distribution, and consumption of fuel, as well as
emissio ns associated with these processes.

Agricultural Sector

Inventory adjustments from final RFS2 rule modeling 2 were used for 2030. For the Tier 3 proposal, adjustments for 2017 were scaled by the ratio of 2017 renewable fuel volumes versus
2030 volumes. Although 2018 was modeled for the final rule rather than 2017 , we continued to use the 2017 adjustments. Impacts on farm equipment emissions were not accounted for,
however. Emission rates from the GREET model (fertilizer and pesticide production) 3 or based on the 2002 National Emissions Inventory (fertilizer and pesticide application, agricultural dust, livestock waste) were combined with estimates of agricultural impacts from FASOM (Forest and Agricultural Section Optimization Model). Since FASO M modeling used a reference case of 13.2 billion gallons of ethanol, impacts used in the modeling for this rule are underestimates. Adjustment factors are provided in Table 1 . Adjustments were applied equally to all counties having any of the affected so urces. This is one area of uncertainty in the inventories, since there would likely be variation from one county to another depending on how much of the predicted agricultural changes occurred in which counties. By using percent change adjustments rather

t han attempting to calculate absolute ton changes in each county we have attempted to minimize the inventory distortions that could occur if the calculated change for a given county was out of proportion to the reference case emissions for that county. For instance, a different approach could estimate reductions that were larger than the reference case NEI emissions, since there was no linkage between the NEI inventories and the FASOM modeling. The specific sources (SCCs) and affected pollutants that these adjustments were applied to are listed in a docket reference. 4

Table 1. Adjustments to Modeling Platform Agricultural Emi ssions for the Tier 3
R eference Case
Source Description 2018 Adjustment 2030 Adjustment Nitrogen Fertilizer Application 1.0417 1.0573
Fertilizer Production 1.0438 1.0603
Pesticide Production 0.9967 0.9954 Tilling/Harvesting Dust 1.0193 1.0265 Agricultural Burning 1.000 1.000
Livestock Dust 0.9988 0.9983
Livestock Waste 0.9988 0.9983

Biofuel Production

Emissions from the production of biofuels include the emissions from the production facility itself as well as the emissions from production and transport of the biomass and any other fuels used by the biofuel plant, such as natural gas, coal, and electric ity.3

Corn E thanol Plants

Significant changes were made to ethanol plant inventories for the Tier 3 final rule. For the 2007 base year inventory, we used emission estimates in the 2007 platform (obtained from the 2008 NEI version 2) where available.

However, this inventory does not contain emission estimates for all facilities known to be in operation in 2007. For those facilities (e xcept for ethanol )

, emission rates in Table 2 were used to develop inventories. For all pollutants except air toxics, emission rates in this table were obtained from an upstream impacts spreadsheet develop ed for the RFS2 rule. 5 For air toxics except ethanol, toxic to VOC ratios were developed using emission inventory data from the 2005 National Emissions Inventory (NEI). These ratios were then applied to V OC emission rates in
Table 2 , to obtain toxic emission rates. Ratios for different plan t types are given in Table 3

. Ethanol emission rates were obtained from SMOKE speciation profiles.

It should be noted that the R F S 2 r u l e models future year emissions based on the assumption that fossil fuel prices will drive corn ethanol producers to switch to biomass feedstocks from conventional boiler fuels. Due to the difficulty in predicting potential changes i n energy sources for individual plants, this assumption was not included in air quality inventories.

Emission rates f

o r t h e T i e r 3 r u l e were multiplied by facility production estimates as of 2007

, using industry characterization data initially developed for the RFS2 rule an d last updated in early 2012. 6 Total domestic corn ethanol production in 2007 was approximately 6.9 billion gallons.

Initial geographic coordinates for ethanol plants were developed using data from the RFS2 rule and GoogleEarth searches. However, GIS

- based automated quality assurance (QA) checks found many ethanol plants assigned to coordinates that were outside of their assigned state

county FIPS. Additional research using GoogleEarth, web searches, and the NEI were used to
determine cor rect coordinates, and in some cases a reassignment of the state

- county FIPS. 1
Extensive additional effort would be required to detect incorrect assignments within counties. Spreadsheets with coordinates for plants can be found in the docket for the rule. 7

1 In some cases, bad coordinates were easily

- identifiable typos such as switched latitude and longitudes or a missing negative sign for the longitude. In a couple of cases, ethanol plants FIPS and coordinates were in error. It is important to note that onl y ethanol plants that were erroneously assigned outside of their assigned counties were corrected. Other facilities may be assigned to incorrect coordinates within their correctly

- assigned counties.4

Table 2

. Corn Ethanol Plant Criteria Pollutant Emission Factors (grams per gallon produced)

Corn Ethanol Plant Type Year VOC CO NO
x PM 10 PM 2.5 SO
x NH 3

Dry Mill N atural G as (NG) 2007 , 201 8 2.29 0.58 0.99 0.94 0.23 0.01 0.00

2030 2.29 0.58 0.94 0.94 0.23 0.01 0.00 Dry Mill NG (wet distillers grains with soluble ( DGS) ) 2007 , 201 8 2.27 0.37 0.63 0.91 0.20 0.00 0.00

2030 2.27 0.37 0.60 0.91 0.20 0.00 0.00

Dry Mill Biogas 2007 , 201 8 2.29 0.62 1.05 0.94 0.23 0.01 0.00

2030 2.29 0.62 1.00 0.94 0.23 0.01 0.00 Dry Mill Biogas (wet DGS) 2007 , 201 8 2.27 0.39 0.67 0.91 0.20 0.00 0.00

2030 2.27 0.39 0.63 0.91 0.20 0.00 0.00

Dry Mill Coal 2007 , 201 8 2.31 2.65 4.17 3.81 1.71 4.52 0.00

2030 2.31 2.65 3.68 3.64 1.54 3.48 0.00 Dry Mill Coal (wet DGS) 2007 , 201 8 2.31 2.65 2.65 2.74 1.14 2.87 0.00

2030 2.28 1.68 2.34 2.62 1.03 2.21 0.00

Dry Mill Biomass 2007 , 201 8 2.42 2.55 3.65 1.28 0.36 0.14 0.00

2030 2.42 2.55 3.65 1.28 0.36 0.14 0.00 Dry Mill Biomass (wet DGS) 2007 , 201 8 2.35 1.62 2.32 1.12 0.28 0.09 0.00

2030 2.35 1.62 2.32 1.12 0.28 0.09 0.00

Wet Mill NG 2007 , 201 8 2.35 1.62 1.77 1.12 0.28 0.09 0.00

2030 2.33 1.04 1.68 1.00 0.29 0.01 0.00

Wet Mill Coal 2007 , 201 8 2.33 1.04 5.51 4.76 2.21 5.97 0.00

2030 2.33 3.50 4.86 4.53 1.98 4.60 0.00

Table 3

. Toxic to VOC Ratios for Corn Ethanol Plants

Acetaldehyde Acrolein Benzene 1,3

- Butadiene Formaldehyde Wet Mill NG 0.02580 0.00131 0.00060 2.82371E

- 08 0.00127 Wet Mill Coal 0.08242 0.00015 0.00048 2.82371E

- 08 0.00108 Dry Mill NG 0.01089 0.00131 0.00060 2.82371E

- 08 0.00127 Dry Mill Coal 0.02328 0.00102 0.00017 2.82371E

- 08 0.00119

The industry characterization updated in 2012 was also used to project the 2007 inventory to future years, based on new plants, changes in production capacity since 2007 or changes in progress. These changes result in production of approximately 15 billio n gallons in 2018 and
2030. If emission estimates already existed in the 2007 platform, they were scaled up using changes in production, whereas if they were new plants or missing from the platform, emission rates from Table 2 were multiplied by productio n capacity estimates.

Finally it should be noted that, subsequent to air quality modeling, duplicate emissions were found for a very small number of plants. This error has an insignificant impact on modeling
results.5

Cellulosic Biofuel Refineries

As in previous air quality modeling exercises

, cellulosic plants were treated as area sources and spread across the entire area of the county where they were located . Cellulosic biofuel refinery

s iting was determined based on utilizing the lowest cost feedstock, accounting for the cost of the feedstock itself as well as feedstock storage and the transportation of the feedstock to the cellulosic biofuel refinery. The total number of cellulosic biofuel refineries was projected using volumes from modeling using AEO 2013, early release . The methodology used to determine most likely plant locations is described in Section 1.8.1.3 of the RFS2 RIA 8

.
In previous upstream modeling for the proposed Tier 3 rule, cellulosic plants were assumed to produce both ce llulosic ethanol and cellulosic diesel. For this Tier 3 final rule modeling cellulosic biofuel refineries were categorized as either thermochemical or biochemical based on the available feedstock. Plants that were assumed to have forest or municipal soli d waste feedstock available were projected to be thermochemical plants and plants that were projected to have agricultural residue feedstock available were projected to be bio chemical plants

. Emissions factors for each cellulosic biofuel refinery reflect the fuel production technology used rather than the fuel produced.

Emission factors were updated to reflect this chan ge in cellulosic inventories. VOC and HAP

e mission factors from the cellulosic diesel work in the Tier 3 NPRM were used as the emission
f actors for the thermochemical plants (Tables 4 and 5)

. C ellulosic ethanol VOC and related HAP
emission factors from the Tier 3 NPRM were used as the biochemical VOC and related HAP
emission factors

. 2

Table 4

. Criteria Pollutant Emission Factors for Cellulosic Plants (Tons/ RIN gal lon )

Cellulosic Plant Type VOC CO NO
x PM 10 PM 2.5 SO
x NH 3

Thermochemical 5.92E

- 07 8.7E

- 06 1.31E

- 05 1.56E

- 06 7.81E

- 07 1.17E

- 06 1.44E

- 10
Biochemical 1.82E

- 06 1.29E

- 05 1.85E

- 05 3.08E

- 06 1.23E

- 06 6.89E

- 07 0

Table 5

. Toxic Emission Factors for Cellulosic Plants (Tons/ RIN gal lon )

Cellulosic Plant Type Acetaldehyde Acrolein Benzene 1,3

- Butadiene Formaldehyde Ethanol

Thermochemical 2.95E

- 08 1.27E

- 09 9.61E

- 10 0 5.07E

- 09 2.09E

- 07
Biochemical 3.98E

- 07 1.11E

- 08 1.39E

- 08 0 2.28E

- 08 6.41E

- 07

2 It should be noted that in the Tier 3 NPRM we meant to use different cellulosic ethanol non

- VOC CAP emission factors depending on which feedstock the plant was using but instead we used the same emission factors (based on a forest waste feedstock) for all the plants. For the FRM we corrected that by using emission factors for the non

- VOC CAPS that were based on a stover feedstock for the biochemical plants.6

Biodiesel Plants

Emission rates for biodiesel pl ants were obtained from the impacts spreadsheet and are provided
in Table 6 . Plant location and production volume data came from the Tier 3 proposed rule and are provided in a docketed spreadsheet called “ABS2013 Biodiesel_Plant_Inv 04 10 13.xlsx”. Total volume of biodiesel came from the AEO 2013 early release, 1.3 BG for both 2018 and
2030. 9 To reach the total volume of biodiesel, plants that had current production volumes were assumed to be at 100% production and the remaining volume was split among plants with planned production.

Table 6 . Emission Factors for Biodiesel Plants (Tons/Mgal)

Pollutant Emission Factor

VOC 4.3981E

- 02

CO 5.0069E

- 01

NO x 8.0790E

- 01

PM 10 6.8240E

- 02

PM 2.5 6.8240E

- 02

SO x 5.9445E

- 03

NH 3 0
Acetaldehyde 2.4783E

- 07

Acrolein 2.1290E

- 07

Benzene 3.2458E

- 08
1,3

- Butadiene 0 Formaldehyde 1.5354E

- 06

Ethanol 0

Petroleum Refineries

Air quality modeling inventories account for impacts of increased use of biofuels , and reduced gasoline and diesel fuel consumption from greenhouse gas standards, on emissions from petroleum refineries. While there will also be impacts on emissions associated with crude oil extraction and transport to refineries, for Tier 3 modeling these impacts wer e not included . The same assumption was made in air quality mode ling for the RFS2 rule.7

Since projection year inventories in the modeling platform do not account for impacts of EISA on gasoline production, we f i r s t calculated what gasoline volumes would be with 2007 ethanol volumes in 2018 and 2030 (accounting for displac ement of gasoline with lower energy content of ethanol.) 10 Then the impacts of the changes in gasoline volume in 2018 and 2030 with 2007 ethanol volumes versus projected volumes with EISA were calculated using an updated version of the impacts spreadsheet developed for the RFS2 rule. 11 The resulting impacts were used to calculate scaling factors to apply to criteria pollutant emissions for SCCs associated with refinery gasoline and distillate production.

In addition to the impacts of EISA, the 2017

- 2025 light

- duty greenhouse gas rule and heavy

- duty greenhouse gas rule will significantly reduce gasoline and diesel production. The impact of
th ese rule s will be very small in 2018, but quit e significant in 2030. To account for impacts of this rule in 2030, an additional scalar of 0.7944 was applied. The combined scalars applied to account for EISA and the greenhous e gas rules are given in Table 7

. Toxic emissions were estimated in SMOKE by applying speciation to VOC emissions.

Table 7

. Adjustment Factors Applied to Petroleum Refinery Inventories for the Tier 3 Reference Case.

Pollutant 201 8 Adjustment 2030 Adjustment
VOC 0.9 7 0. 77
CO 0. 98 0. 77
NO X 0. 99 0. 78

PM 10 0. 98 0.7 8

PM 2.5 0. 98 0.7 7
SO X 0. 98 0. 77
NH 3 0.95 0.75

Biofuel Transport

Increased use of biofuels has a number of impacts on upstream emissions associated with transport. These impacts include vapor losses of ethanol associated with storage and transport, vapor losses associated with storage and transport of gasoline ethanol blends, and combustion emissions associated with transport of feedstocks to fuel production facilities and ethanol transport via marine vessel, rail, and tanker truck.

Vapor Losses from Transport of Ethanol

Vapor emissions of ethanol occur during storage , as well as loading and unloading

. For the final
Tier 3 rule air quality inventory, county level inventory impacts on ethanol production SCCs8

were estimated using AP

- 42 gasoline transport loss emission factors, adjusted for denatured ethanol vapor pressu re and molecular weight 3 , along with data from a detailed Oak Ridge National Laboratory (ORNL) analysis of projected ethanol transport modes, distances and
volume . The tons of transported ethanol from the ORNL analysis were adjusted to account for
2013 AE O ethanol volumes. 12

Vapor Losses from Transfer and Storage of Gasoline and Gasoline/Ethanol Blends

VOC evaporative emissions are also produced by transfer and storage activities associated with distribution of gasoline and gasoline/ethanol blends. Thes e are referred to as Stage I emissions. Stage I distribution begins at the point the fuel leaves the production facility and ends when it is loaded into the storage tanks at dispensing facilities.

There are five types of facilities that make up this di stribution chain for gasoline. Bulk gasoline terminals are large storage facilities that receive gasoline directly from the refineries via pipelines, barges, or tankers (or are collocated at refineries). Gasoline from the bulk terminal storage tanks is lo aded into cargo tanks (tank trucks or railcars) for distribution to smaller intermediate storage facilities (bulk plants), or directly to gasoline dispensing facilities (retail public service stations and private service stations). When ethanol is blended into gasoline it usually occurs in the pipes which supply cargo tanks at bulk terminals.

Bulk plants are intermediate storage and distribution facilities that normally receive gasoline or gasoline/ethanol blends from bulk terminals via tank trucks or rail cars. Gasoline and gasoline/ethanol blends from bulk plants are subsequently loaded into tank trucks for transport to local dispensing facilities.

Gasoline and gasoline/ethanol blend dispensing facilities include both retail public outlets and private dispensing operations such as rental car agencies, fleet vehicle refueling centers, and various government motor pool facilities. Dispensing facilities receive gasoline and gasoline/ethanol blends via tank trucks from bulk terminals or bulk plants. Invento ry estimates for this source category only include the delivery of gasoline at dispensing facilities and does not include the vehicle or equipment refueling activities.

2018 and 2030 inventories which included EISA impacts were developed by adjusting the 2 007 platform inventory. These adjustments were made using an updated version of EPA’s spreadsheet model for upstream emission impacts, developed for the RFS2 rule. Below we describe how we developed emission factors and fuel volumes to make these adjus tments with the impacts spreadsheet.

3 Net factor =0.20 = 3 psi/10 psi * 48.7 MW/72 MW9

Vapor loss VOC emission factors (EFs) for gasoline were based on inventory estimates from the
2005 NEI , divided by total volume of gasoline

. 13 Emissions were partitioned into a refinery to bulk terminal component (RBT ), a bulk plant storage (BPS), and a bulk terminal to gasoline dispensing pump (BTP) component. Emissions for the BTP component are greater than the RBT and BPS components. Total nationwide emissions for these components were divided by the
energy content of the total volume of gasoline distributed in 2005 , to obtain emission factors in grams per million metric British Thermal Units ( g/mmBTU )

. Total volume of gasoline was based on gasoline sales as reported by the Energy Information Administration. 14 In addition to gasoline VOC emission factors for the RBT/BPS components, emission factors were develo pe d for the BTP component, for 10 percent ethanol , 1 5 percent ethanol , and 85% ethanol . Emission
factors for ethanol blends were calculated by ap plyin g adj ustment factors to gasoline EFs . The adjustment factors were based on an algorithm from the 1994 EPA On

- Board Refueling Vapor Recovery Rule 15 :

EF (g/gal) = exp[

- 1.2798

- 0.0049(ΔT) + 0.0203(Td) + 0.1315(RVP)]

where delta T is the difference in temperatu re between the fuel in the tank and the fuel being dispensed, and Td is the temperature of the gasoline being dispensed. We assumed delta T is zero, and the temperature of the fuel bei ng dispensed averages 60 oF over the year.

We use d average summer RVPs at the Petroleum Administration for Defense Districts (PADD) level to calculate adjustments. The U.S. is broken into five PADDs for petroleum products data collection purposes via the U.S. Energy Information Administration; see: http://www.eia.gov/oog/i nfo/twip/padddef.html. These PAD D regions are shown in Figure 1.

The methodology used to develop these RVPs is described in Chapter 7.1.3.2 of the Regulatory Impact Analysis for this rule. All counties within a PADD received the same adjustment for

BTP e missions. For the Tier 3 reference case, expected volumes were based on projections from
Annual En ergy Outlook 2013

. 16 Volumes for each fuel type and summer RVPs for 2018 and 2030 are provided in Table 8 and 9.

Volumes for each fuel type a nd summer RVPs are provided for 2 0 1 8 a n d 2 0 3 0 w i t h 2 0 0 7 e t h a n o l

v o l u m e s in Tables 10 and 11 . RVPs for the s e case s in 201 8 and 2030 were obtained from analysis of 200 7 fuel data. S i n c e 2007 ethanol volumes were assumed for 2018 and 2030, the gasoline volume w a s increased to compensate for the difference in ethanol for 2018 and 2030, versus what is expected.

A b enzene g/mmgal emission factor for 2018 and 2030 w as based on benzene inventory projections used in the 2011 Cross

- State Air Pollution Rule and average 2015

- 2030 gasoline
volumes obtained from the Annual Energy Outlook 2011 Early Release Overview . This
emission factor was used to est imate g/mmBTU emission factors based on the energy content of
E0

, E10 , and E15 gasoline. Aside from energy content, we did not account for the effect of10

Figure 1. Map of Petrole um Administration for Defense Districts (PADD)Table 8 . RVPs Assumed for 2018 with project ed ethanol and gasoline volumes. Used to Estimat e Transfer and Storage VOC
Emissions

.

Table 9

. RVPs Assumed for 2030 with project ed ethanol and gasoline volumes. Used to Estimat e Transfer and Storage VOC
Emissions

.

PADD Total Fuel
Volume Gasoline

Volume Ethanol

Volume E10 Only

Volume E15 Only

Volume E85(74) Only

Volume Weighted

RVP Weighted

E10 RVP Weighted

E15 RVP Weighted

E85 RVP

1 3.92E+10 3.41E+10 5.02E+09 2.43E+10 1.43E+10 6.02E+08 8.444 8.763 7.962 7

2 2.97E+10 2.58E+10 3.91E+09 1.62E+10 1.31E+10 4.56E+08 8.942 9.333 8.525 7

3 1.95E+10 1.68E+10 2.63E+09 9.32E+09 9.85E+09 2.98E+08 8.245 8.644 7.905 7

4 4.69E+09 4.08E+09 6.14E+08 2.64E+09 1.98E+09 7.20E+07 9.063 9.524 8.524 7

5 2.05E+10 1.81E+10 2.47E+09 1.60E+10 4.24E+09 3.17E+08 7.884 7.93 7.774 7

TOTAL 1.14E+11 9.89E+10 1.46E+10 6.84E+10 4.34E+10 1.75E+09 8.464 8.716 8.126 7 PADD Total

Fuel
Volume Gasoline

Volume Ethanol

Volume E10 Only

Volume E15 Only

Volume E85(74) Only

Volume Weighted

RVP Weighted

E10 RVP Weighted

E15 RVP Weighted

E85 RVP

1 4.50E+10 3.99E+10 5.18E+09 3.71E+10 7.43E+09 4.73E+08 8.536 8.651 8.056 7

2 3.46E+10 3.03E+10 4.25E+09 2.31E+10 1.11E+10 3.63E+08 9.051 9.35 8.493 7

3 2.14E+10 1.89E+10 2.48E+09 1.72E+10 3.95E+09 2.25E+08 8.399 8.515 7.973 7

4 5.07E+09 4.48E+09 5.89E+08 4.06E+09 9.53E+08 5.33E+07 9.322 9.536 8.536 7

5 2.35E+10 2.08E+10 2.71E+09 1.91E+10 4.13E+09 2.47E+08 7.906 7.974 7.645 7

TOTAL 1.30E+11 1.14E+11 1.52E+10 1.01E+11 2.75E+10 1.36E+09 8.567 8.696 8.175 7Table 10 . RVPs Assumed for 2018 with 2007 ethanol volu mes. Used to Estimat e Transfer and Storage VOC Emissions

Table 11 . RVPs Assumed for 2030 with 2007 ethanol volumes. Used to Estimat e Transfer and Storage VOC Emissions PADD Total Fuel

Volume Ethanol

Volume Gasoline

Volume E0 Only

Volume E10 Only

Volume Weighted

RVP Weighted E0

RVP Weighted E10

RVP

1 4.42E+10 2.47E+09 4.17E+10 1.95E+10 2.47E+10 8.63 8.301 8.883

2 3.38E+10 1.92E+09 3.19E+10 1.47E+10 1.92E+10 9.48 8.925 9.907

3 2.09E+10 1.02E+09 1.99E+10 1.07E+10 1.02E+10 8.77 8.391 9.166

4 4.96E+09 2.54E+08 4.71E+09 2.43E+09 2.54E+09 9.18 8.674 9.674

5 2.30E+10 1.27E+09 2.17E+10 1.03E+10 1.27E+10 7.77 7.602 7.911

TOTAL 1.27E+11 6.93E+09 1.20E+11 5.76E+10 6.93E+10 8.75 8.372 9.059

PADD Total Fuel

Volume Ethanol

Volume Gasoline

Volume E0 Only

Volume E10 Only

Volume Weighted

RVP Weighted E0

RVP Weighted E10

RVP

1 3.83E+10 2.47E+09 3.59E+10 1.36E+10 2.47E+10 8.68 8.301 8.883

2 2.90E+10 1.92E+09 2.71E+10 9.88E+09 1.92E+10 9.57 8.925 9.907

3 1.89E+10 1.02E+09 1.79E+10 8.78E+09 1.02E+10 8.81 8.391 9.166

4 4.57E+09 2.54E+08 4.32E+09 2.04E+09 2.54E+09 9.23 8.674 9.674

5 2.02E+10 1.27E+09 1.89E+10 7.48E+09 1.27E+10 7.80 7.602 7.911

TOTAL 1.11E+11 6.93E+09 1.04E+11 4.18E+10 6.93E+10 8.80 8.372 9.059other fuel parameters on emission rates for E0, E10, and E15 blends . Thus, the E1 0 emission

rate is slightly higher than the E0 rate due to the lower energy content of E1 0, and the E15 emission rate is higher still

. The E85 emission rate was estimated for the RFS2 rule. Emission
facto rs are summarized in Table 12.

Table 12

. Storage and Transport Vapor Loss Emission Factors (g/mmBtu)

Process Fuel Benzene

BTP E0 0.250

E10 0.259
E15 0.264
E85 0. 023
RBT/BPS E0 0.059

Emission factors for VOC and benzene were used in conjunction with an updated version of EPA’s spreadsheet model for upstream emission impacts, developed for the RFS2 rule, to
estimate PADD level level inventory changes of the changes in gasoline volume in 2018 with 2007 ethanol volumes versus projected volumes with EISA. 17 VOC inventory changes were used to develop nationwide adjustment factors that were applied to modeling platform inventory
SCCs asso ciated with storage and transport processes (Table 13 ). This created the 2018 reference case inventory. Benzene emission estimates were obtained either by application of the adjustments in T able 12 or through speciation of VOC in SMOKE, following criteri a described in EPA’s Technical Support Document for the 2005 modeling platform. 18

A similar approach was used to develop adjustment factors for 2030. However, in addition to the impacts of EISA, the 2017

- 2025 light

- duty greenhouse gas rule will significa ntly reduce gasoline production. The impact of this rule was small enough to ignore for 2018, but quite significant in 2030. To account for impacts of this rule in 2030, an additional scalar of 0.7916 was applied.

Ethanol emissions were estimated in SMOKE by applying the ethanol to VOC ratios from headspace profiles to VOC emissions. These ratios are 0.065 for E10 and 0.272 for E15. The profiles were obtained from an ORD analysis of fuel samples from the EPAct exhaust test

program 19 and have been submitted for incorporation into EPA’s SPECIATE database. The E85 profile was obtained from data collected as part of the CRC E

- 80 test program 20 and has also been submitted for incorporation into EPA’s SPECIATE database.

It should be noted that these adjustment factors are based on summer RVP, but applied to emissions for the whole calendar yea r. However, higher RVPs in winter corresponding to lower temperatures result in roughly the same vapor pressure of the fuel and roughly the same propensity to evaporate. Significant evaporative emissions are not expected from storage and transport of bio diesel, renewable or cellulosic diesel fuel due to their low volatility.14

Table 13

. Adjustment Factors Applied to Storage and Transport Emissions

Year Process PADD Pollutant Adjustment Factor 2018 BTP 1 VOC 0.9515 benzene 0.9905
2 VOC 0.9619

benzene 0.9882
3 VOC 0.9778

benzene 0.9879
4 VOC 0.8983

benzene 0.9885
5 VOC 0.9430

benzene 0.9901
RBT/BPS All VOC 0.9553 benzene 0.9893
2030 BTP 1 VOC 0.8005 benzene 0.7871
2 VOC 0.8436

benzene 0.7865
3 VOC 0.8318

benzene 0.7824
4 VOC 0.7905

benzene 0.7840
5 VOC 0.7700

benzene 0.7888
RBT/BPS All VOC 0.8114 benzene 0.7863

Combustion Emissions from Transport of F uels

Emissions are produced by the vehicles and engines used to transport feedstocks such as crude oil, corn, and cellulosic biomass to fuel production facilities, as well as transport/distribution of the finished fuels from the production plants to distributio n terminals and retail outlets. For example, corn would be transported from farms and grain facilities to ethanol plants by truck and possibly rail. The finished ethanol would be transported from there to bulk distribution terminals by truck, rail, or b arge, and distribution from terminal to retail outlet is by truck. We did not account for emissions associated with feedstocks, but did account for transport of finished fuels.

Combustion Emissions from Water and Rail Transport of F uels

To develop the C1

, C2 and rail air quality modeling reference case inventories for th is Tier 3
final rule, C1

, C2 and rail platform inventories were adjusted to account for (a) differences in C1,15

C2 and rail emission rates in 201 8 and 2030 versus 2007 , (b) the difference in ethanol volume impacts for AEO 2013 future year projections versus the 2007 platform volume of 8.7 Bgallons ( d o m e s t i c a n d i m p o r t e d ) and (c) impacts on gasoline production and distribution from the 2017

- 2025 light duty vehicle GHG emissions standards

. 21 Adjustments to C1, C2 and rail emission rates were calculated using t on/ton

- mile e mission factors that were obtained from the Tier 3 proposed rule inventory and AEO 2013 projected domestic shipping estimates

. 22

, 23 The ethanol
volume impacts were allocated to individua l counties using factors developed from the ORNL analysis. 24 Impacts on C1, C2 and rail emissions from the 2017

- 2025 light duty vehicle GHG
emission standards were calculated using the RFS2 impacts spreadsheet. Impacts from the 2017

- 2025 light duty vehicle GHG emission standards were assumed to be negligible in 2018 and were accounted for by the scalars in T able s 14 and 15 for 2030

.

Table 14

. Scalars Applied to Rail Combustion Emissions in 2030 to account for 2017

- 2025 LDGHG emission standards

Pollutant Scalar
CO 0.998
NOx 0.998
PM2.5 0.997
PM10 0.996

SO2 0.997
VOC 0.997

Table 15

. Scalars Applied to C1/C2 Combustion Emissions in 2030 to account for 2017

- 2025 LDGHG emission standards

Pollutant Scalar
CO 0.996
NOx 0.993
PM2.5 0.994
PM10 0.993
SO2 0.991
VOC 0.978

Combustion Emissions from Truck Transport of F uels

Tank trucks are used to transport fuel from production facilities to bulk terminals and from terminals to bulk plants and dispensing facilities. Impacts of this activity on emissions from tank trucks (Class 8) are a ccounted for in reference case inventories by adjusting VMT used in
SMOKE

- MOVES. 25 The VMT adjustments were derived from the ORNL analysis of ethanol transport, scaled to ac count for the difference in ethanol volume impacts for AEO 2013 future16

year projections versus the 2007 platform volume of 8.7 Bgallons and impacts on gasoline production and distribution from the 2017

- 2025 light duty vehicle GHG emissions standards

. Impa cts from the 2017

- 2025 light duty vehicle GHG emission standards were assumed to be negligible in 2018 and were accounted for with a 0.997 scalar in 2030.

Combustion Emissions Associated with Transport of Gasoline by Pipeline

In addition to combustion emis sions associated with transport of gasoline by water, rail and tanker truck transport, there are also combustion emissions associated with transport of gasoline by pipeline. These emissions are impacted by 2017

- 2025 light duty vehicle greenhouse gas
emission standards , as well as EISA. To account for impacts of the 2017

- 2025 light

- duty standards, scalars developed for that rule were applied to refinery and bulk terminal SCCs

. They were applied to these SCCs d ue to the difficulty in isolating the emi ssions along pipelines from pumps and other equipment by SCC

. Impacts in 2018 were assumed to be negligible

. Additional impacts of EISA were added to these scalars. Estimated impacts of these rules were obtained from by first estimating overall impacts on combustion emissions associated with
transport, using the RFS2 impacts spreadsheet, then using nationwide emission fractions for combustion emission fractions associated with pipelines from GREET 1.8.c to obtain the portion attributable to pipelines. 26

, 27 The scalars are provided in Table 16

.

Table 16 . Scalars Applied to Pipeline Combustion Emissions

Pollutant 2018 2030
CO 0.996 0.981
NOx 0.981 0.890
PM2.5 0.998 0.989
PM10 0.997 0.985
SO2 0.998 0.986
VOC 0.999 0.994

Portable Fuel Container Impacts

There are several sources of emissions associated with portable fuel containers (PFC) used for gasoline. These sources include vapor displacement and spillage while refueling the gas can at the pump, spillage during transport, permeation and evapo ration from the gas can during transport and storage, and vapor displacement and spillage while refueling equipment

. Increased use of ethanol in gasoline fuels can increase evaporative emissions from PFCs for a number of

reasons. If , E10 fuels have highe r volatility than corresponding E0 fuels, that can increas e evaporation and vapor displacement. Second, ethanol in gasoline increases permeation of fuel through gas can materials. Finally, the lower energy content of ethanol fuels leads to more frequent refueling, and, thus, greater emissions from spillage and displacement while filling the gas can at the pump.17

The use of ethanol also changes the mix of hydrocarbons in the evaporated fuel. In particular it can change the fraction of ethanol, benzene and n aphthalene as described below.

As part of the 2007 regulation controlling emissions of hazardous pollutants from mobile sources (MSAT2 rule), EPA promulgated requirements to control VOC emissions from gas cans. The methodology used to develop emission inventories for gas cans is descri bed in the regulatory impact analysis for the rule and in an accompanying technical support document. 28

, 29 The large majority of spillage emissions occur when refueling equipment, and this is already included in the nonroad equipment inventory. Thus we di d not include these emissions in the PFC inventory
for this rule. Vapor displacement for nonroad equip ment container refueling was also subtracted from vapor displacement in the PFC inventory to avoid double counting these emissions

.
For the RFS2 rule, ba sed on the MSAT work, we generated two sets of hypothetical nationwide annual estimates of PFC VOC emissions, for calendar years 2017 and 2030, based on all E0 and
all E10. 30 Interpolation was used to estimate PFC VOC emissions that reflected the mix of E0
and E10 for reference and control cases. To develop inventories for this rule , the national VOC
estimates for all E0 in 2017 and 2030 were adjusted to create inventories that reflected 100%
E10

. We concluded that the 2017 inventory could be used to adeq uately represent 2018. These inventories were adjusted to account for impacts of RVP and oxygenate, using adjustment factors derived from modeling done with the NONROAD2008b model. 31 NONROAD was run at the national level using average nationwide fuel para meters for an all E0 case and the E10 reference case. The percent change in refueling emissions from gasoline equipment was used to adjust the vapor displacement emissions, the percent change in tank permeation was used for PFC permeation, and the perce nt change in diurnal emissions was used for evaporation. Summer RVPs were used to develop these adjustments. Because significant PFC use occurs in winter, this will overestimate emission impacts. In 201 8 and 2030, the E0 case assumed an nationwide

averag e 8.7 psi RVP. The reference inventory in 201 8 assumes E10 with 8. 70 psi RVP for E10 and 2030 E10 with 8.72 psi RVP

. Adjustment factors developed using these inputs are provided
in a docket reference. 32

MSATs found in liquid gasoline will be present as a component of VOC emissions. These MSATs include benzene, ethanol, and naphthalene. For vapor displacement, toxic to VOC ratios were obtained from headspace vapor profiles from EPAct test fuels

. 33 For permeation emissions, vehicle permeation speciation data from Coordinating Research Council (CRC) technical reports

E

- 77

- 2b and E

- 77

- 2c were used. 34

, 35 We relied on three day diurnal profiles from the CRC data. For evaporative emissions resulting from changes in ambient temperatures, speciation data from
th e Auto/Oil program were used for E0 and E10. 36 Table 17 lists the toxic to VOC ratios for each type of PFC emission.18 Table 17

. Toxic to VOC ratios for PFCs

Pollutant Process Speciation Surrogate E0 E10

Benzene Vapor Displ. Vehicle Headspace 0.0077 0.0087

Permeation Vehicle Permeation 0.0250 0.0227
Evaporation Vehicle Evap 0.0336 0.0340

Naphthalene Vapor Displ. Vehicle Headspace 0.0000 0.0000

Permeation Vehicle Permeation 0.0004 0.0004
Evaporation Vehicle Evap 0.0004 0.0004

Ethanol Vapor Displ. Vehicle Headspace 0 0.0645

Permeation Vehicle Permeation 0 0.2020
Evaporation Vehicle Evap 0 0.1190

Table 1 8 presents national air quality modeling inventories for PFCs in 201 8 and 2030. National
emissions were allocated to the county level.

Table 18

. PFC Emissions in 201 8 and 2030 for the FRM Air Quality Inventories (Tons)

Scenario VOC Benzene Ethanol Naphthalene 2018 29,119 641 3,687 7 2030 37,946 829 4,969 9

1 U. S. Energy Information Administration. 2013. Annual Energy Outlook, 2013, Early Release. Report No. DOE/EIA

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3 GREET, version 1.8c. Available at < http://greet.es.anl.gov/ >.

4 U. S. EPA. 2011. Spreadsheet “agricultural sector adjustments.xls.” Docket EPA

– HQ

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5 U. S. Environmental Protection Agency. 2010. Renewable Fuel Standard Program (RFS2) Regulatory Impact Analysis. Assessment and Standards Division, Office of Transportation and Air Quality, Ann Arbor, MI. Report No. EPA

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< http://www.epa.gov/otaq/fuels/renewablefuels/regulations.htm >.

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7 U . S. EPA. 2013. Spreadsheet “2018rg_ethanol_facilities_12nov2013.xls” Docket EPA

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0383 ER(2013 ) Available at < http://www.eia.gov/forecasts/aeo/er/ >

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.

11 U. S. EPA. 2013. Spreadsheet “upstream_emissions_rev T3.xls. Do cket EPA

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13 U. S. EPA. 2005 National Emissions Inventory. Available at < http://www.epa.gov/ttn/chief/net/2005inventory.html#inventorydata >

14 Source: Energy Information Administration. 2006. Annual Energy Outlook 2006. Report #:DOE/EIA

0383(2006) Available at <http://www.eia.gov/oiaf/archive/aeo06/aeoref_tab.html>

15 EPA. 1 994. Final Regulatory Impact Analysis: Refueling Emission Regulations for Light Duty Vehicles and Trucks and Heavy Duty Vehicles. Office of Mobile Sources, Ann Arbor, MI. Available at <http://www.epa.gov/otaq/orvr.htm>

16 U.S. Energy Information Administration, Annual Energy Outlook 2013 (April 15, 2013)

. < http://www.eia.gov/forecasts/aeo/data.cfm >

17 U. S. EPA. 2013. Spreadsheet “upstre am_emissions_rev T3.xls.

18 U. S. Environmental Protection Agency. 2010. Technical Support Document: Preparation of Emission Inventories for the Version 4, 2005

- based Platform. Office of Air Quality Planning and Standards, Air Quality Assessment Division , July 7, 2010. Available at

< ftp://ftp.epa.gov/EmisInventory/2005v4/2005_emissions_tsd_07jul2010.pdf >

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- Fuel Vehicles. Agust, 2011. http://www.crcao.org/reports/recentstudies2011/E

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24 “Analysis of Fuel Ethano l Transportation Activity and Potential Distribution Constraints,”

Oak Ridge National Laboratory, U.S. Department of Energy, March 2009. Docket EPA

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31 http://www.epa.gov/otaq/nonrdmdl.htm#model

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36 Auto/Oil Air Quality Improvement Research Program. 1996. Phase I and II Test Data. Prepared by Systems Applications International, Inc.